Yemen's embattled President Ali Abdullah Saleh has been wounded in shelling at the presidential compound in the capital, Sana'a, Reuters reports.

Numerous media accounts quoted an opposition television report as saying President Saleh was at a mosque in the presidential compound when rockets landed during Friday afternoon prayers.

Yemeni officials say several high-ranking officials also were wounded in the attack.

Early reports say the injured include the prime minister and the speaker of parliament. It is presently unclear who was responsible for the shelling.

Earlier Friday, clashes between Saleh's forces and loyalists to an opposition tribal leader, Sheik Sadeq al-Ahmar, escalated with the destruction of the headquarters of an opposition TV station in Sana'a. Fighting in the capital has expanded into new neighborhoods, and opposition tribesmen are traveling to Sana'a to take part in the fighting, reports said.

The sudden escalation of violence in the entrenched conflict between Saleh loyalists and opposition groups resulted in Yemen's airports being closed on Thursday as choas spread. The rising violence, which began in late January, has brought Yemen to the brink of all-out civil war. Government troops are said to have killed 50 opposition members in fighting this week.

Yemen is engulfed by multiple conflicts, with street battles raging in Sana'a, popular unrest by anti-government demonstrators throughout the country and fighting against Islamist militants who have seized the southern city of Zinjibar.

In the southern city of Taiz, government forces and protesters clashed Thursday. At least 25 people have died in the violence in Taiz in the past few days.

Renewed fighting in Sana'a broke out last week when pro-Saleh forces moved against al-Ahmar's compound in Hasaba, a district of the capital. In March, the al-Ahmar family had announced that the Hashid confederation - the country's most powerful tribal alliance - would back the protest movement, but its armed fighters had avoided clashes with Saleh's forces.